Add-on: when will it be released?

Heroes 5 has long been surpassed by the vast majority of players; they want something new, with a similarly captivating plot (to put it mildly, but still!). And it seemed that in the final video, a subtle hint of a continuation of the great saga appeared. I wonder, why are patches needed? (but they are certainly needed to improve the gameplay to perfection...). But the developers are not thinking about an add-on yet, but they will remember soon, because it would be a sin to leave such a story without a continuation... :)